Methodological reliability evaluation of trust and reputation management systems

Abstract

Trust and Reputation Management (TRM) systems are used in various environments, and their main goal is to ensure efficiency despite malicious or unreliable agents striving to maximize their usefulness or to disrupt the operations of other agents. However, TRM systems can be targeted by specific attacks, which can reduce the efficiency of the environment. The impact of such attacks on a specific system cannot be easily anticipated and evaluated. The article presents models of the environment and the TRM system operating in the environment. On that basis, measures of the reliability of TRM systems were defined to enable a comprehensive and quantitative evaluation of the resistance of such systems to attacks. The presented methodology is then used to evaluate an example TRM system (RefTRM), through the created and briefly described tool TRM-RET (Trust and Reputation Management – Reliability Evaluation Testbed). The results indicate that the system's specific properties can be indicated on the basis of the tests and metrics proposed; for example, the RefTRM system is quite vulnerable to an attack tailored to the parameters used by this system.